Bioeconomic Sustainability and Resilience of Biodiversity under Invasive Species Pressures

As a major cause of species extinction, invasive species pose a significant threat to biodiversity and ecosystems. In a context of limited resources and mistrust toward environmental measures, the management of invasive species requires compromises between conservation objectives, economic constraints, and the acceptability of the measures taken. In this article, we develop a stylized bioeconomic model of native-invasive species dynamics to analyze management strategies that enable the long-term preservation of native species. Considering a viable control framework, we characterize the conditions under which coexistence of the two species or eradication of the invasive species are sustainable, taking into account budgetary and conservation constraints. We identify a "viable corridor" -a set of states in which native species can be sustainably preserved -and deduce the corresponding viability control efforts. By contrasting the solutions obtained via viability and optimal control frameworks, we highlight how viability principles can lead to more sustainable and resilient outcomes. A numerical application to the case of grey versus red squirrels in the United Kingdom illustrates the policy relevance of our findings.